28820660 has 48 divisors (see below), whose sum is σ = 66407040. Its totient is φ = 10419840.

The previous prime is 28820651. The next prime is 28820683. The reversal of 28820660 is 6602882.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 58937 + ... + 59423.

It is an arithmetic number, because the mean of its divisors is an integer number (1383480).

Almost surely, 2^28820660 is an apocalyptic number.

28820660 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 28820660, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33203520).

28820660 is an abundant number, since it is smaller than the sum of its proper divisors (37586380).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

28820660 is a wasteful number, since it uses less digits than its factorization.

28820660 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 776 (or 774 counting only the distinct ones).

The product of its (nonzero) digits is 9216, while the sum is 32.

The square root of 28820660 is about 5368.4876827650. The cubic root of 28820660 is about 306.5970515159.

The spelling of 28820660 in words is "twenty-eight million, eight hundred twenty thousand, six hundred sixty".